Hit indicator arrangement



X R 3 Q .5 b g 76 l P 6, 1969 R. e. STINCHCOMB HIT INDICATOR ARRANGEMENT Filed Feb. 3, 1967 2 Sheets-Sheet 1 RAYMOND G. STINCHCOMB I N VENTOR.

United States Patent 3,466,761 HIT INDICATOR ARRANGEMENT Raymond G. Stinchcomb, Glen Burnie, Md., assignor to AAI Corporation, Cockeysville, Md., a corporation of Maryland Filed Feb. 3, 1967, Ser. No. 613,804 Int. Cl. F41g 3/26; A6315 9/02; H04b 1/00 US. Cl. 35-25 11 Claims ABSTRACT OF THE DISCLOSURE A hit indicator arrangement is disclosed for simulated hit-kill field practice which permits the use of a stand ard rifle with pulse initiating means attachable to the trigger assembly for initiating a target interrogation pulse when the trigger is squeezed. The arrangement is an improvement particularly applicable to hit indicator arrangements as shown in US. Patent No. 3,104,.- 478.

In a hit indicator system of the type disclosed in U.S. Patent No. 3,104,478, apparatus is attached to a rifle so that when a rifleman fires his rifle at a target a pulse is produced which causes an omnidirectional radio frequency target interrogation signal to be transmitted. The radio frequency signal causes an infrared source mounted on the target to radiate a signal. If the rifle is properly aimed, a photoelectrically responsive element, disposed at, or near, the focal plane of a telescopic lens arrangement, such being hereinafter referred to as a photoscope or photoelectric telescope, which is attached to the rifle, will receive the infrared signal and produce an electrical output signal which may desirably cause the apparatus to produce another radio frequency signal which informs the target that a hit has been scored. In addition, or alternatively, the weapon-connected apparatus may desirably produce a signal informing the rifleman that a bit has been scored.

The purpose of such hit indicator systems is to permit the tactical field training of personnel on a realistic basis. As it is highly desirable that the hit indicator system be used with a standard rifle, such as an M-14 rifle, it is desirable that the pulse initiating device be attachable to the rifle without modification of the rifle or the use of special tools. Accordingly, it is a feature of this invention to provide a pulse initiating device which can be easily installed on a standard rifle by a rifleman without the need for special tools.

To conduct the tactical field training of personnel on as realistic a basis as possible, blank ammunition is used in the rifles. However, the loud noise and/ or the reactive forces resulting from the cartridge firing often causes the rifle to be moved through flinching and/or recoil force action to some degree and thereby disturbs the aim of the rifle. As a result, the photoscope attached to the rifle may not receive the infrared signal from the target and thus a hit will not be registered even though the rifle was on target at the time of firing and would have scored a hit with live ammunition. Therefore, it is highly desirable that the infrared target signal be received at the rifle before the firing of the rifle can disturb the aim of the rifleman. Preferably it should be received before the hammer strikes the firing pin. In order for this to be accomplished, the signal sequence should begin with or very shortly after the release of the hammer by the hammer sear of the rifle. Accordingly, it is a feature of this invention to provide a pulse initiating arrangement which will produce an electrical pulse for initiating generation of an interrogation signal pulse very shortly after the rifleman squeezes the trigger.

ICC

In accordance with the present invention there is provided a pulse initiating device having a bracket adapted to fasten onto the hammer actuator plunger housing of the trigger group assembly of a rifle. Attached to the bracket is an over-center toggle action switch which is connected as a part of a pulse producing circuit that supplies a pulse to a modulator which causes a radio frequency signal to be transmitted. The switch is actuated as a function of the motion of the plunger housing and has a first electrical conductance condition when the trigger group assembly is in a cocked position and a second electrical conductance condition during the firing action of the trigger group assembly. As the trigger group assembly changes from a cocked position to the firing position, the switch is operated so as to initiate a pulse by the pulse producing circuit which causes the radio frequency signal to be transmitted.

Still other objects, features and attendant advantages will become apparent to those skilled in the art from a reading of the following detailed description of one physical embodiment constructed in accordance with the invention, taken in conjunction with the accompanying drawings where:

FIG. 1 is a schematic illustration of an embodiment of the invention as applied to a rifle hit indicator arrangement.

FIG. 2 is a schematic view in side elevation of the rifle trigger group arrangement embodying a pulse iniating device according to the invention, and showing the position of the parts when the hammer is in a cocked position.

FIG. 3 is an exploded view of the rifle trigger group arrangement showing the pulse initiating device and the position of the parts when the hammer is in a cocked position.

FIG. 4 is a side elevation view of the pulse initiating device which is attachable to the trigger assembly of the weapon.

FIG. 5 is an end view of the pulse initiating device.

FIG. 6 is a view similar to that of FIG. 2, showing the position of the parts when the hammer is in'the firing position.

FIG. 7 is a circuit schematic of an electrical network embodying the invention.

Referring now in detail to the figures of the drawings, as shown in FIG. 1 the equipment which will normally be worn and carried by a rifleman during simulated tactical field training when employing a hit indicator system according to US. Patent No. 3,104,478, and the present invention includes a rifle generally indicated at 11 with a muzzle 13, aiming elements 15 and 17, a trigger group assembly generally indicated at 19, and a sling 21 attached to the rifle as by fasteners 23 and 25. A photoscope 27 containing an infrared detector 29, shown in FIG. 7, is rigidly clamped to the muzzle 13 of the weapon 11 and electrically connected by means of a conductive cable 31 attached to the side of the weapon 11, to a portable pack 35 having a strap 36 and containing a battery pack 37 and electrical apparatus used in a hit indicator system of the type described in the referenced patent. Mounted in the trigger group assembly 19 of the weapon 11 is a pulse initiating device 39 (see FIGS. 2-6) which is connected by conductive cable 41 to the portable pack 35. Also shown in FIG. 1 is a helmet 43 upon which is mounted an omnidirectional radio frequency antenna 45 and an infrared source 47, both of which are connected by means of conductive cable 49 to the por able pack 35.

As shown in FIGS. 2-6 the pulse initiating device generally indicated at 39, includes a bracket 51 with a narrow curved portion 53 which is used to properly position the pulse initiating device 39 in the trigger group assembly 19. A clip 55 is riveted to the upper part of the bracket 51 and is adapted to fasten the pulse initiating device 39 onto the trigger group assembly 19 of the rifle 11. Riveted to the lower part of the bracket 51 is an over-center toggle action switch 57, such a Microswitch, with an actuating feeler pin 59 slidably extending through a hole 61 in the switch housing 63. As shown in FIG. 4, in the cutaway portion of the housing 63 can be seen a pair of fixed terminals 65 and 67 attached to the side of the housing 63. A movable contact 69 is connected by a pair of curved leaf springs 71 and a center leaf tension member 73 to the fixed terminal 67. The center leaf 73 is held under tension by the curved leaf springs 71. The curved springs 71 normally press the movable contact 69 against a fixed contact 75 extending from terminal 65. One end of the pin 59 engages the center leaf tension member 73, and pressure on the opposite end of the pin 59 will cause the pin 59 to press the movable contact 69 away from the fixed contact 75 with a quick snap action separation being effected by the over-center toggle action of the switch 57. Attached to one end of the housing 63 of the switch 57 and bent beneath it is a leaf spring 77 which has a rolled portion 79 on the end. Connected to the two fixed terminals 65 and 67, but on the external side of the housing 63 of the switch 57 are a pair of connectors generally indicated at 81 by which the conductive cable 41 is attached to the fixed terminals 65 and 67 of the switch 57.

As illustrated in FIGS. 2 and 3, in which an illustrarive conventional trigger group assembly 19 of the rifie 11 is shown in a cocked position with the pulse initiating device 39 atached thereto, the illustrative trigger group assembly 19 includes a housing assembly generally indicated at 83 and having a fiat horizontal portion 85, a vertical bracket 87, and a support bracket 89. A hammer 91 is pivotally attached to the vertical bracket 87 of the housing assembly 83 as by a pin 93. Pivotally mounted as by a pin 95 to the support bracket 89 of the housing assembly 83 is a hammer actuator generally indicated at 97. The hammer actuator 97 includes a plunger 99 having a head 101 and a rod 103, a compression spring 105, and a cylindrical plunger housing 107, having a bore 109. The head 101 of the plunger 99 engages a cupped recess 111 formed in the hammer 91. The plunger rod 103 is contained inside the spring 105, one end of which engages the bottom portion of the head 101 of the plunger 99. Both the spring 105 and the plunger 99 are disposed inside the bore 109 of the cylindrical plunger housing 107 with the other end of the spring 105 resting against the bottom 113 of the bore 109. The plunger housing 107 i self is pivotally mounted to the support bracket 89 of the housing assembly 83 as by the pin 95.

The pressure exerted against the hammer 91 by the spring 105 and plunger 99 in combination resiliently biases the hammer 91 clockwise as viewed in FIGS. 2, 3 and 6, toward the firing position as illustrated in FIG. 6. Holding the hammer 91 in a cocked position, as shown in FIG. 2, is a scar 115 which engages a hook 117 on the end of the hammer 91. Sear 115 is pivotally attached to the support bracket 89 of the housing assembly 83 by the pin 95. A trigger 119 is also pivotally attached to the housing support bracket 89 by a pin 121 and is suitably mechanically connected as in a conventional manner to the sear 115, as indicated by the broken line 123, so as to cause the sear 115 to release the hammer 91 when the trigger 119 is pivoted clockwise. These trigger group elements per se are desirable conventional, being in the illustrative embodiment of those found in the M-l4 and NATO rifles, and accordingly only the parts of the trigger group assembly 19, necessary for an understanding of this invention, are shown and described herein, it being appreciated that the invention may be employed in conjunction with various other trigger group assemblies, making suitable obvious moditications as may be necessary or desirable.

Pulse initiating device 39 is attached to the plunger housing 107 by means of clip 55. The bracket 51 is positioned on the plunger housing 107 so that the narrow curved portion portion 53 of the bracket 51 rests against the support bracket 89 of the housing assembly 83. In the cocked position, as shown in FIG. 2, the rolled end 79 of the leaf spring 77 rests against the top surface of the fiat, horizontal portion of the housing assembly 83. In this position, the leaf spring 77 exerts pressure on the bottom end of the pin 59 which in turn causes the opposite end of the pin to press against the center leaf tension member 73, thereby forcing the contacts 69 and 75 apart to an open circuit condition.

When the trigger 119 is pivoted clockwise so as to cause the sear to release the hammer 91, the spring 105 acts on plunger 99 to swing the hammer 91 upward and forward to the firing position as shown in FIG. 6 where it strikes a firing pin 151 which in turn fires a cartridge 153. As the hammer swings upward, the housing 107 also moves upward through a small angle, such as approximately 20, and releases the pressure exerted on the pin 59 by the leaf spring 77. As a result, the springs 71 press the contacts 69 and 75 together. The time at which the switch contacts 69 and 75 close may be set or varied as necessary or desired by adjustment or variation of any one or more of: the length and shape of the leaf spring 77 (including the curvature of the rolled portion 79 on the end of the leaf spring 77), the initial extent of displacement of the contact 69 from the contact 75, and the contact position of pin 59 in relation to the leaf spring 71 and the center leaf tension member 73.

As shown in FIG. 7, the pulse initiating device switch 57 forms a part of a DC. pulse producing circuit generally indicated at 125 that supplies a pulse to a modulator 127 which turns on a radio frequency transmitter 129 thereby causing a pulse signal to be transmitted omnidirectionally from the antenna 45. This signal is received by an antenna 131 at the target and detected in a receiver 133. The receiver 133 actuates a pulse generator 135 which causes the infrared source 137 to radiate a pulse signal. If the rifie 11 is properly aimed at the target, the infrared light signal is received by the infrared detector 29 which is contained in the photoscope 27. The infrared signal impinging on the infrared detector 29 causes an electrical pulse to be supplied to both the modulator 127 and the hit indicator 139 of the rifieman. The pulse supplied to the modulator 127 causes another radio frequency signal to be transmitted to the target, which will actuate the target hit indicator 141, thereby informing the target that a hit has been scored. The pulse supplied to the rifiemans hit indicator 139 will actuate it and inform the rifieman that a hit has been scored. This circuitry, with the exception of the antenna 45, which is mounted on the helmet 43, the photoscope 27, which is mounted on the barrel 13 of the rifle 11, the pulse initiating device 39 which is mounted in the trigger group assembly 19 of the rifle 11 and connecting cables 31, 41 and 49, may be suitably contained in the portable pack 35.

The pulse producing circuit 125 consists of a power source 37 which may be of any suitable size and type, e.g. a 12 volt battery, with a voltage divider consisting of a pair of resistors 143 and 145 serially connected across the terminals of the source 37. For purposes of illustration, the resistors 143 and 145 may be considered to be of equal value, and thus an average value of 6 volts will be maintained at the junction 147 between the resistors 143 and 145. A capacitor 149 is connected in parallel across the resistor 145 and forms an RC charging circuit with resistor 143. Normally the capacitor 149 charges to the average value maintained at the junction 147. However, if the capacitor 149 is suddenly short circuited, it rapidly discharges thereby producing a sharp negative pulse at the junction 147.

Connected in parallel across the capacitor 149 is the pulse initiating device switch 57. The pulse initiating device switch 57 controls the charging and discharging of 5 the capacitor 149 by acting as either an open circuit or a short circuit. When the trigger group assembly 19 is in the cocked position and the switch contacts 69 and 75 are forced apart by the. pressure exerted on the pin 59 by the leaf spring 77, 'a constant voltage, that is the voltage at junction 147, is applied to the modulator'127. When the trigger group assembly 19 moves to the firing position the pressure forcing the switch contacts 69 and 75 apart is removed and the contacts spring together thereby short circuiting the capacitor 149 and supplying a sharp, negative pulse to the modulator 127 and thereby initiating the target interrogation signal sequence.

In operation, each rifleman participating in simulated tactical field training, employing a hit indicator system of the type described, will be wearing a helmet 43 upon which is mounted an omnidirectional radio frequency antenna 45 and an infrared source 47. Each rifle 11 will have a photoscope 27 clamped onto the barrel l3 and a pulse initiating device 39. of the type hereinbefore described, fastened onto the plunger housing 107 of the 'trigger group assembly 19. The remainder of the elec trical apparatus shown in FIG. 7 is preferably contained in a portable pack 35, which will be carried by each rifleman by means of the strap 36, and connected to the other elements of the circuit by means of the conductive cables 31, 41 and 49. While participating in the tactical field training a rifleman will normally carry his rifle 11 in a cocked position, as shown in FIG. 2. In this position, the hammer 91 is resiliently biased by the hammer actuator 97 and held by the sear 115 which engages the hook 117 on the end of the hammer 91. The hammer actuator 97 is in a lowered position which causes the leaf spring 77 to exert pressure on the bottom of the pin 59 which in turn forces the contacts 75 and 69 of the pulse initiating device switch 57 apart. With the contacts 75 and 69 of the switch 5 7' thus forced apart, the switch 57 is open circuited and the capacitor 149 is charged from the source 37 of electrical energy through the resistor 143 to the average potential as determined by the junction 147 of the voltage divider.

During the course of the tactical field training, a rifleman will spot a target, take aim, and fire his rifle 11. When he squeezes the trigger 119, the sear 115, which is mechanically linked to the trigger 119, will release the hammer 91 which will then swing upward and forward as a function of the resilient biasing force exerted on it by the hammer actuator 97, thereupon striking the firing pin 151 and driving it forward to fire the cartridge 153. As the hammer 91 swings upwardly and forwardly, the hammer actuator 97 will also swing upward thereby removing the pressure exerted on the switch actuator pin 59 by the leaf spring 77. As a result, the switch contacts 75 and 69 close and short circuit the capacitor 149 which rapidly discharges through the switch 57 causing a sharp negative pulse to be supplied to the modulator 127. The modulator 127 turns on the radio frequency transmitter 129 and thereby causes a radio frequency target interrogation pulse signal to be transmitted omnidirectionally from the antenna 45 mounted on the helmet 43 of the rifieman. This signal is received at the target by an antennaa 131 and detected in a receiver 133. The receiver 133 actuates a pulse generator 135 which causes the infrered source 137 attached to the target to radiate a pulse signal. if the refieman has properly aimed his rifle 11, the infrared light signal will be received by the photoscope 27 clamped to the barrel 13 of his rifle 11. The infrared detector 29 contained in the photoscope 27 converts the infrered light signal into an electrical pulse which is the supplied to both the modulator 127 and the hit indicator 139 of thc ribeman. The pulse supplied to the modulator 127 causes another radio frequency pulse signal to be transmitted to the target which actuates the target hit indicator 14] thereby informing the target that a hit has been scored. The pulse supplied to the rifieman's hit indicator I3 actuates it and informs the rifleman that a hit has been scored. it is important to note that by utilizing the present invention the entire signal sequence may occur within a very short time after the trigger squeezing and before the firing of the cartridge, and preferably being completed before the firing of the cartridge.

While the invention has been illustrated and described with respect to a single preferred embodiment, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. For example, although a pulse producing circuit 125 has been disclosed which will supply a negative pulse to the modulator 127, it will be obvious to others skilled in the art that the pulse producing circuit 125 can be modified so as to supply a positive pulse to the modulator 127. Also, although a normally closed switch 57 has been used to illustrate the invention, it is obvious that a normally open switch can be used. Accordingly, it is to be understood that the invention is not to be limited by the illustrative embodiment, but only by the scope of the appended claims.

That which is claimed is:

1. In a simulated hit indicator arrangement including a rifle having a barrel with photoelectric target signal responsive telescope detector arrangement mounted thereon, and a trigger group assembly for firing a cartridge; a target-interrogating transmitter; and a receiver operatively connected to the output of said photoelectric telescope, the improvement comprising:

a pulse initiating device switch connected 'to said trigger group assembly and includirg a switch having a first electrical conductance condition in a first position and a second electrical conductance condition in a second position and being arranged in controlling relation to said transmitter,

said pulse initiating device switch being moved from said first position to said second position as a function of movement of a portion of said trigger group assembly during firing motion of the trigger group assembly, completion of change of conductance of said switch to said second electrical conductance condition being effected prior to firing of said cartridge by continued motion of said trigger group after movement of said switch from said first position to said second position.

2. In a simulated hit indicator arrangement .as defined in claim 1 wherein:

said pulse initiating device switch forms a part of a pulse producing circuit comprising a resistor and a capacitor serially connected across a source of electrical energy thereby forming a charging circuit for said capacitor,

said pulse initiating device switch permitting said capacitor to charge during one electrical conductance condition and causing said capacitor to discharge during the second electrical conductance condition, thereby causing a sharp electrical pulse to be produced upon change of said conductance conditions.

3. In a simulated hit indicator arrangement as defined in claim 1,

said pulse initiating device switch being mounted on a movable element of said trigger group assembly and being movable with said element to effect motion thereof from said first position to said second position.

4. In a simulated hit indicator arrangement including a rifle having a barrel with photoelectric target signal responsive telescope detector arrangement mounted thereon, and a trigger group assembly for firing a cartridge; a target-interrogating transmitter; and a receiver operatively connected to the output of said photoelectric telescope, the improvement comprising.

a pulse initiating device switch connected to said trigger group assembly and including a switch having a first electrical conductance in a first position and a second electrical conductance condition in a second position and being arranged in controlling relation to said transmitter, said pulse initiating device switch being moved from said first position to said second position as a function of movement of a portion of said trigger group assembly during firing motion of the trigger group assembly, a completion of change of conductance of said switch to said second electrical conductance condition being effected prior to firing of said cartridge by continued motion of said trigger group after movement of said switch from said first position to said second position. said trigger group assembly comprising a hammer and a spring-biased movable hammer actuator, said pulse initiating device switch being mounted on said hammer actuator and being operatively changed in conductance by movement of said hammer actuator and prior to said hammer firing said cartridge. 5. In a simulated hit indicator arrangement as defined in claim 4,

said hammer actuator being pivotally mounted in said trigger group assembly and said pulse initiating device switch comprising a switch actuating element movably responsive to the pivotal movement of the hammer actuator to cause the switch to change from said first electrical conductance condition to said second electrical conductance condition prior to firing of said cartridge by said hammer. 6. In a simulated hit indicator arrangement as defined in claim 5,

said pulse initiating device switch being electrically connected to a pulse producing circuit comprising a resistor and a capacitor serially connected across a source of electrical energy and thereby forming a charging circuit for said capacitor, said pulse initiating device switch permitting said capacitor to charge during one electrical conductance condition and causing .said capacitor to discharge during the second electrical conductance condition, thereby producing a sharp electrical pulse. 7. In a simulated hit indicator arrangement as defined in claim wherein:

said spring-biased hammer actuator comprises a plunger which engages said hammer, a spring which encloses the plunger and engages it at one end, and a housing pivotally mounted in said trigger group assembly which engages the opposite end of the spring and encloses a portion of the plunger and the spring, said pulse initiating device switch being removably secured to said hammer actuator housing.

8. In a simulated hit indicator arrangement as defined in claim. 7,

said pulse initiating device being removably secured to said actuator housing by a clip, and said pulse initiating device being shaped so as to properly position 5 said pulse initiating device switch in the trigger group assembly when clipped onto the actuator housing. 9. In a simulated hit indicator arrangement as defined in claim 1, 10 said pulse initiating device switch having an over-center toggle action which snaps the switch from one electrical conductance condition to the other electrical conductance condition when the switch operates. 10. In a simulated hit indicator arrangement including a rifle having a barrel with photoelectric target signal responsive telescope detector arrangement mounted thereon, and a trigger group assembly, including a hammer which strikes a firing pin, for firing a cartridge: and a receiver operatively connected to the output of said photoelectric telescope, the improvement comprising:

a pulse initiating device in controlling relation to a target-interrogating transmitter, said pulse initiating device being responsive to movement of a portion of said trigger group assembly during the firing motion of the trigger group assembly to produce a pulse, said target-interrogating transmitter being responsive to said pulse to produce a target-interrogating signal prior to the firing of a cartridge by the hammer striking the firing pin. 11. In a'simulated hit indicator arrangement as defined in claim 10,

said target being responsive to said target-interrogating signal to effect a return electromagnetic signal for reception by the receiver of said photoelectric telescope, said return signal being transmitted and re ceivable by said telescope and receiver in a time span terminating prior to the firing of the cartridge.

References Cited UNITED STATES PATENTS 9/1932 Bock .s 325-170 X 9/1963 Strauss et al. 25

US. Cl. X.R. 273--l0l.2; 325-66, 164 

